Hybrid Fiber Coax (HFC) cable networks were originally built to deliver broadcast-quality TV signals to homes. The wide availability of such systems and the extremely wide bandwidth of these systems led to the extension of their functionality to include delivery of high-speed broadband data signals to end-users. Data over Cable System Interface Specifications (DOCSIS), a protocol developed under the leadership of Cable Television Laboratories, Inc., has been established as the major industry standard for two-way communications over HFC cable plants. Use of the DOCSIS protocol and quality-of-service management has further allowed HFC cable systems to deliver telephone service to subscribers over a packet switched network using the Internet protocol.
Large cable networks comprise distributed video and data facilities. In a typical network architecture, video is distributed to subscribers in geographically segmented markets via a dedicated headend that services multiple hubs and nodes. Regional data centers support multiple headends through separate fiber links for delivery of data and telephone services. Coordination of subscriber video services and subscriber data services (e.g., e-mail, web browsing, VoIP) is required for billing purposes and, increasingly, to provide cross-over services that use both video facilities and data facilities. For example, a video terminal device (“VTD”) not only provides video services to the subscriber, but may provide the subscriber access to e-mail, web-browsing, and voice services.
Increasingly, entertainment programs delivered by program distribution networks include interactive features, which often relate to the programming content that is being shown to a user. For example, an “INFO” icon may appear on the TV screen while a regional football game is being shown, a selection of which by a remote control results in a display of scores of other regional football games being played. A similar icon may appear on the TV screen while a commercial is being shown, a selection of which results in a display of program-related content (PRC), e.g., information relating to a product or service being promoted in the commercial. To ensure a timely presentation of an interactive feature, the corresponding interactive application data may be received and stored in the user's set-top box in advance of its presentation or may be delivered via headends using VOD infrastructure.
Interactive television offers subscribers a variety of ways to interact with television programming. For example, subscribers may view web pages that complement a program, receive e-mail links to web pages related to a particular program, participate in polls, surveys, games and quizzes, order product samples, catalogs, brochures and other items, join online chats while watching a particular program, engage in e-commerce, and store upcoming programs on their personal video recorder.
These interactive services are provided in many forms. For example, RespondTV is Internet-based and requires a WebTV Plus box or a digital set-top box with a cable modem. Wink provides services through servers placed in the facilities of the local cable operators, which servers convey responses back through the Wink system.
In the past, the interactive application data was transmitted to a set-top box by time-division multiplexing the data with a transport stream via an out-of-band channel or using a VOD architecture. What would be useful is a system and method that would provide PRC to subscribers without disrupting the display of video programming, without depending on the storage resources of a VTD for displaying the PRC, without depending on a headend NDVR, and without further use of the limited video bandwidth that is available.